1. Field of the Invention
The present invention relates to a network print system to output images including documents and the like prepared by a computer connected on a network such as LAN or so by use of an optional printer connected on the same network.
2. Description of the Related Art
Recently there are many network print systems to output images made by computers in a configuration of a network environment such as LAN involving plural computers and plural printers.
In the network print systems in the prior art, at the event of image data created (a print job) by a certain computer so as to be printed by a printer, the print job was immediately sent to the printer designated on the network or a print server to store and control the print job.
In each printer or print server, the received print job is stored initially into a First-In First-Out (FIFO) print queue consisting of a buffer memory and the like, and a print job that has come first into the print queue is printed first.
In this manner, in the print job management methods by the conventional network print systems, at the event of a print job on a computer, the print job is sent to a printer or a print server set on the network as print data. Accordingly, there were many cases where many print jobs were accumulated in a certain printer or print server designated on the network, even though print queues of other printers were empty.
Furthermore, in each printer or print server, print jobs were executed in the sequence of coming into the print queue, therefore, even a print job of one sheet had to wait in the case when another print job of numerous sheets had come into the print queue of the printer just before it. Namely, printing was executed always by a predetermined printer, so even when there were other printers ready for printing, a user who wanted to print out only one sheet had to wait for a long time, which was one of the negative effects in the prior art.
Still further, since printing was executed in the sequence of print jobs coming into a print queue of the printer or print server, when plural users utilized a single printer, they may have left their own printed matters in that printer. Namely, the information of printed matters may have been accessed by other persons, as a result, it was difficult to keep secrecy, which was another problem in the prior art.
Also, print jobs were controlled at the printer side, and the contents of the print queue were printed at once, therefore, if printed matters were output by mistake, unnecessary printed matters were output automatically. Moreover, it was very difficult to completely delete a print job created by mistake from the computer side, which was another problem in the prior art.
And further, when plural copies of an identical document were necessary, for instance, in a conference or so, in the conventional network print system, it was necessary to copy the printed matter output by the printer by use of a photoelectric copying machine or to execute the same print job many times.